latchNode.md

SR Latch (latchNode)

Category: Logic

Intended behavior

Set/Reset latch: Set holds the state true, Reset holds it false, until the other fires.

Inputs

ID	Label	Type	Unwired default
setTrigger	Set	trigger	undefined
resetTrigger	Reset	trigger	undefined

Outputs

ID	Label	Type	Default
outTrigger	Out	trigger	undefined
state	State	boolean	undefined

Configuration defaults

{
  "state": false
}

Observed frontend behavior

This calls the production passive computation with the declared input/config defaults. Cached state, trigger execution and project wiring are separate.

{
  "kind": "passive-default-probe",
  "outputs": {
    "state": false
  }
}

Observed backend behavior

Offline production passive computation with the same declared defaults; no device or model service is invoked.

{
  "kind": "passive-default-probe",
  "outputs": {
    "state": false
  }
}

Current frontend implementation

Extracted production branches; helper calls and project execution context are defined in the referenced modules.

src/lib/extra-node-compute.ts:49

latchNode: (_inputs, config) => ({ state: Boolean(config.state) })

src/lib/extra-trigger-ops.ts:30

latchNode: (_inputs, config, port) => {
    // Anything other than Reset is a Set — the latch only has two commands.
    if (port !== "setTrigger" && port !== "resetTrigger") {
      return { nextTriggerPort: "outTrigger" };
    }
    return {
      nextTriggerPort: "outTrigger",
      updatedConfig: { ...config, state: port === "setTrigger" },
    };
  }

Implementation references

• src/lib/extra-node-compute.ts:49
• src/lib/extra-trigger-ops.ts:30
• backend/engine/extra.py:157
• backend/engine/trigger_state.py:38

Verification limits

• Default passive probe is an observation, not proof of all configurations, trigger behavior, or correctness. See ../NODE_RUNTIME_AUDIT.md and ../AUDIT_VALIDATION.md for test evidence.
• Trigger inputs schedule actions; passive evaluation alone does not execute those actions. Wire a trigger source and test the full chain.

Source fingerprint: 7e9d192bd3a559a7c50253919867601ef02c311d61e859f7afb4cadcfa508430. Rebuild with npm run docs:index.